Administration of low doses of Cu(II)-DOPA-ATP to normal rats markedly elevated dopamine levels in the caudate nucleus, nucleus accumbens and olfactory tubercle when compared with equimolar doses of L-DOPA. In reserpine plus tranylcypromine-pretreated rats in which dopamine levels were depleted, Cu(II)-DOPA-ATP restored dopamine levels to normal while DOPA had no effect in the dosage used. Both DOPA and DOPA-chelate decreased copper levels in the brain nuclei.